Exhaust nozzle for jet engines



1961 J. o. JEWELL 3,003,312

MUST NOZZLE FOR JET ENGINES Filod Aug. 19, 195'! 4 Shoots-Shut I Jab/t D. c/ewe/l 1961 J. o. JEWELL 3,003,312

EXHAUST NOZZLE FOR JET ENGINES mod Aug. 19, 1957 4 Shoots-Shut 2 .322: 2&1" Jae/t .D. c/ewe/l o 1951 J. o. JEWELL v 3,003,312

mus: uozzus: FOR m memes Filod Aug. 19, 1957 4 Shuts-Shut 3 Jack D. c/ewel/ b M azn s Oct. 10, 1961 p, JEWELL 7 3,003,312

BIG-MUST NOZZLE FOR JET (um um Au 19. 19s? 4 spmi-snm 4 JFJ.5

Jack D. Jewell v #45 3,003,312 EXHAUST NOZZLE FOR JET ENGINES Jaclr D. Jewell, Perry, Ohio, assignor to Thompson Ramo Wooldrldge lne, a corporation of Ohio Filed Aug. 19, 1957, Ser. No. 678,915

2 Claims. (Cl. 60-3554) The present invention relates to improvements'in controllable jet nozzles for jet propulsion units. More particularly, the invention relates to improvements in jet nozzles which'are controllable in their various functional factors thatcontrol the how of gas to obtain the thrust power, and especially to improvements in the control of the nozzle to affect the forward thrust, directional control, reversal of thrust, nozzle area, sound attenuation, and operational safety of the nozzle.

The improved nozzle assembly embodying the principles of the invention may be utilized in a jet propulsion engine. an aircraft or the like, and also may be employed for test purposes. The structural features employed in accordance with the principles of the invention mutually contribute to effect an improved operation of the nozzle in areas including each of those referred to above. I

Accordingly, it is an object of the invention'to provide an improved jet nozzle for the propulsion of hot gases toobtain a controllable thrust which has improved performance features and has an improved controllability over nozzles heretofore used.

Another object of the invention is to provide a controllable jet propulsion nozzle with improved directional control features.

r A further object of the invention is to provide a jet propulsion no'zzle for use in aircraft or the like, whereinthe thrust can be controllably reversed and wherein the directional control nozzle and its associated features contribute to the performance of the thrust reversing mechanism.

A further object of the invention is to provide an improvednozzle wherein the nozzle area is controllably variable, and wherein the area control contributes to the thrust performance of the nozzle, and also obtains improved thrust reversing and improved noise characteristics.

Another object of the invention is to provide an improved jet thrust nozzle having an improved nozzle opening shape for enhancing the performance of the nozzle and improving noise attenuation, and especially for relieving screech conditions at choked noule settings.

' A further object of the invention is to provide an improved method and apparatus for controlling the forward and reverse thrust of the nozzle and for providing a safety feature wherein forward thrust will be restored in the event of failure of the reverse thrust controls.

A still further object of the invention is to provide improved operational controls for a jet noule for obtaining direction control, reversal of thrust, variance of the nozzle area, and adjustment of controlled jet flow for either directional thrust or net forward or reverse thrust.

A further object of the invention is to provide an improved mechanism for operation under certain circumstances as a secondary air ejector to cool the jet exhausts anddecrease the sound power.

Another object of the invention is to provide a jet nozzle with a shape whichwill create small jets in addition to a large jetwith means to create a turbulence to separate the small jets from the larger jets, and for decreasing sound power.

Another object of the inventionis to provide an improved control for a variable jet nozzle, wherein directiona1 control is automatically prevented during areas of reverse thrust operation.

Patented Oct. 10, 1961 Other objects and advantages will become more apparent with the teachings of the principles of the invention "in connection with the disclosure of the preferred embodiments thereof, in the specification, claims anddrawings. in

which: 7

FIGURE 1 is a plan view, shown somewhat in set...

matic form, with portions removed, of a jet propulsion noule embodying the principles of the invention;

FIGURE 2 is a plan view, similar to FIGURE 1, but with parts removed, illustrating the directional control of the nozzle in a horizontal plane;

, FIGURJE 3 is a side elevational view'of the nozzle with parts removed, and illustrating the directional control in a vertical plane;

FIGURE 4 is an exploded view illustrating assembly parts of the nozzle;

FIGURE 5 is a plan view, similar to FIGURE 1, but with the reverse thrust target members'included;

FIGURE 6 is a plan view somewhat in schematic form, of the nozzle with substantially all elements included;

FIGURE 7 is a side elevational view of the nozzle of FIGURE 6;

FIGURE 8 is a plan view of the nozzle illustrating the position of the thrust reversing target members in zero thrust position;

FIGURE 9 is a side elevational view of a part of a variable area nozzle;

FIGURE 10 is a rear elevational view of the variable area nozzle illustrating it adjusted to minimum area;

FIGURE 11 is a sectional view taken along line XI XI of FIGURE 10, but with the'nozzle adjusted to maximum area so that the scallop projections coincide;

FIGURE 12 is a sectional view taken substantially along line XlI-.-XII of FIGURE 11, from the inside of the nozzle to illustrate the vortex generator;

FIGURE 13 is a schematic illustration of the throttle control arrangement; and 7 FIGURE 14 is a schematic arrangement of the nozzle control.

The variable nozzle assembly is most fully shown in FIGURE 6 at 18, as variably controlling the flow of gas supplied by a combustion chamber 20, which may include an afterburner.

The propellant, which may be in the form of a fluid or as commonly used with a thrust engine, in the form of hot gases generated in the combustion chamber, flows through a duct 22, as illustrated in FIGURES 1 and 6. The duct is illustrated as surrounded by a fuselage protecting tube 24, which coaxially surrounds the duct and which is omitted from the drawing in FIGURE 1. The fuselage protecting tube has rearwardly extending triangular shaped guard extensions 26, 26, which are located on each side of the rearwardly moving jet stream when the tube 24 and other operational elements carried on transient bars 28 and 30, are in extended position.

The tube 24 is shown supported for its axial movement in a coaxial position relative to the duct on tube guides 32 and34, which are mountedsuch as by supports 36 and 88 for the guide 34, and 40 and 42 for the guide 32,

on the duct 22. The transient bars or rails are carried on the tube and move axially therewith.

Axial movement in the direction of the flow of the jet stream, for the transient rails, is obtained by rail actuator cylinders and 46, FIGURES 1 6 and 7. These cylin:

FIGURE 14 controls the flow of hydraulic fluid to other operational cylinders which function to position the other operational elements of the nozzle in a manner which will be described.

As illustrated in FIGURES 1 through 4, a control nozzle or nozzle extension assembly 52 is provided. This nozzle is variable in position in a radial direction to give a controlled lateral thrust. The control nozzle 52 is also variable in size so as to regulate the size of a central nozzle opening 54, which is of the shape illustrated in FIGURE 10.

The control nozzle 52 includes two parts, an inner shell 56 and an outer shell 58. The inner shell 56 has a shape whereby the inner and outer surfaces form sections of a sphere. The outer shell 58 is similar in shape and somewhat larger, so as to fit over the inner shell in the manner illustrated in FIGURE 1. The outer shell 58 is normally fixed with respect to the inner shell, but at times will be rotated relative thereto about the central axis 60 to change the size of the jet opening 54. This relative rotation of the outer shell is controlled by a nozzle rotation cylinder 62, FIGURE 1. The cylinder is mounted on the inner shell support and deflector ring 64. The inner shell 56 is secured to the rear face 66 of the inner shell support in a concentric position and is supported thereby. The shell rotation cylinder 62, has a piston to which is secured a piston rod 68 secured to the outer shell 58. The flow of fluid to the cylinder 62 thus controls the rotational position of the outer shell in a manner which will later be described.

The inner shell support and deflector ring 64 is pivotally mounted on trunnions 76 and 72 within the outer gimbal ring 74. The inner shell support and deflector ring 64 acts as the inner gimbal ring and is pivoted about a horizontal axis on the trunnions 70 and 72 to direct the gases upwardly or downwardly and thereby control the vertical thrust. Pivotal movement of the inner shell support and deflector ring 64 is obtained from a vertical actuator cylinder 76, which is secured to the outer gimbal ring 74. The cylinder carries a piston slidable therein to which is connected a piston rod 78. The piston rod is illustrated diagrammatically in FIGURE 3, connected to an arm 80 on the inner shell support ring 64 to pivot the ring about its trunnions 70 and 72.

Horizontal variations in thrust are obtained by the outer gimbal ring 74 pivoting about its trunnions 82 and 84. A rotational force to pivot the outer gimbal ring 74 is obtained by an outer gimbal ring operating cylinder 86 which is mounted on the transient support rail 28. The cylinder 86 contains a slidable piston with a piston rod 88 connected to the gimbal ring 74 at a point spaced from the trunnions 82 and 84 to apply a torque to the ring 74. Operation of the cylinder 86 for causing a reciprocation of the piston rod 88 is obtained by a flow of controlled hydraulic fluid, as controlled by the nozzle control shown at FIGURE 14. The cylinder 86 is supplied hydraulic fluid through a pressure supply line 85 and a control valve 83' is connected to the supply line to direct fluid through line 861 or line 8612 which lead to the ends of the cylinder 86. A fluid return line 87 leads back to a reservoir of a pressurized fluid'supply system, not shown. The valve 83 may be electrically operated, and direct pressurized fluid to either end of the cylinder 86 and relieve the other end. The cylinder 76 is also supplied pressurized hydraulic operating fluid from the supply line 85 through a valve 89. The valve 89 may be electrically operated to direct operating fluid through either line 76a or line 76b which lead to the ends of the cylinder 76. Fluid is relieved from the uupresstuized end of the cylinder through the return line 87.

.The inner and outer shell 56 and 58 will thus move together with operation of the gimbal rings 64 and 74. The shells are substantially close together in a gas-tight relationship, and are rotationally slidable with respect to each other. The shell assembly or nozzle extension 52, is

mounted on the support nozzle 96, as illustrated in FIG- URES 1 through 4. The support nozzle has an outer spherical surface 92 in order to receive the inner shell 56 for universal sliding movement thereon. The support nozzle 96 has a nozzle opening 94, which continues from the opening 98 at the end of the duct 22. The forward edge of the spherical section which forms the inner support nozzle 92, is secured, such as by welding, to the edge of the duct 22, which forms the opening 90 at the rear end of the duct.

The inner shell 56 slidably fits on the spherical surface 92 of the support nozzle 96, and an adequate space is provided therebetween for bearing and sealing members, which are not shown in detail. These bearing and sealing elements are fixedly mounted to the surfaces in order that the control nozzle 52 may be moved axially outwardly away from the support nozzle 96 to the position illustrated in FIGURE 6.

When the control nozzle 52 is moved to its extended position on the transient rails 28 and 30, the supporting gimbal rings 64 and 74 for the control nozzle 52 are locked in their neutral position wherein the gas nozzle opening 54 faces directly rearwardly. The controls are so looked that the control nozzle cannot be moved in any direction while in the extended position by the control as shown in FIG. 14. This prevents any accidental upsetting lateral deflective forces from occurring when reverse thrust forces are utilized, as controlled by the engine. Locking of the gimbal rings 64 and 74 is accomplished by locking the control valves S3 and 89. An electrical control switch 91 is mounted on the transient bar 28 and is actuated by a fixed cam 93. When the transient bars 28 and 36 move outwardly to extended position, the cam 93 actuates the switch 91 which is electrically connected to the valves 83 and 89 to prevent operation of the valves. If desired, the switch may be connected to insure that the valves will be positioned so that the gimbal rings are in neutral position with the gas nozzle facing directly rearwardly. The electrical circuitry for connecting the switch 91 and the valves 83 and 89 and a control handle will be apparent to those versed in the art, and the circuitry need not be shown in detail. It will also be appreciated by those versed in the art that mechanical interconnections may be used for the foregoing operations.

Reverse thrusts are obtained by a pair of reversing target members 100 and 102, shown in their inoperative position in FIG. 5, and in their full reverse operative position in FIG. 6. These target members are controllably movable between these two positions and the control of FIG. 14 will be set so that the targets 100 and 102 may be automatically set in any one of three positions, with the first position being the inoperative position of FIG. 5, the second position being a position of zero thrust, as shown in FIG. 8, and the third position being a position of full thrust, as shown in FIG. 6.

The target members 100 and 102, as shown in the plan view of FIG. 5, are mounted for pivotal movement at 104 about a vertical axis. The target members are preferably constructed with an outer concave sector, as shown at 106 for the target member 160, and at 108 for the target member 192. As shown in FIG. 7, the target members are mounted on side arms 110, 112 and 114, 116. The target member 100 has pivotal operating arms 118 and 120 connected at its base. Push rods 122 and 124 reciprocate axially to pivot the target member 100. The other target member 102 has pivotal arms 128 and 130 to which are connected push rods 132 and 134. The push rods 122, 124, 132 and 134 are reciprocated simultaneously and are operated by thrust reversal controlling cylinders 136 and 138. These reversal controlling cylinders 136 and 138 are mounted on the transient rails 28 and 30 and are connected to the push rods for operating the thrust reversal targets 100 and 16 2. The push rods may be provided with stops for accurately positioning the reversing gas targets 100 and 102. Stops for arms 124 and 132 are shown at 144 and 146, and stops for rods 122 and 134 are shown at 140 and 142. These stops are in the form of blocks orlugs which maybe operative toengage control switches or control valves (not shown) to send a positional responsive signal back to the'operational control, as set by the nozzle control mechanism, as shown in FIG- URE l. The stops may also operate to automatically stop thetarget members in the position set by an operational control handle (not shown). The position in which the tar gets stop may be overridden by the manual control mechanism to move the targets beyond their stop position. .For example, when the control handle is set to inovethe target members to zero thrust position, the targets in moving from the inoperative position, shown in FIGURE 5, will automatically be stopped in the zero thrust position ofjFIGURE 8. The manual control handle may be pushed further to override the automatic stop signal and move the targets to zero thrust position, as illustrated in FIGURES 6 and 7, or to some intermediate The control handle may be suitably connected to operate valves .131 and 133, FIGURE 5, which are connected to a pressurized hydraulic fluid supplyline 135, and are connected to return lines 137 which lead back to a reservoirfor the fluid supply which is not shown. The valvesdirect operating fluid to one end of the cylinders 136 and 138 and then vent the other end, and valve 131 to cylinder. 136 through lines 136a and 136b and valve 133 connects to the ends of cylinder 138 through lines 138a and 138b. The valves 131 and 133 are electrically operated and are connected in circuit with the control handle. Also connected in the circuit is a switch 139 which is mounted in a fixed position to be actuated by the stop lug 142, FIGURE 8. The lug 142 is positioned relative to switch 139 so that when the target members 100 and 102 are in the position of zero thrust, the switch will be actuated to operate the valves 131 and '133 to stop movement of the target members. This zero thrust position can be overridden by movement of the handle. The electrical circuitry for this operation will be apparent to those versed in the art, and, therefore, need not be shown in detail. It will also be apparent that mechanical interconnection may be used instead of electrical circuitry for the above operation. The switch 139, FIGURE 8, is connected by leads 139a to the valves 131 and 133, FIGURE 7.

A fail-safe mechanism is provided to prevent the targets from accidentally moving to reverse position on failure of the control operating mechanism. The fail-safe mechanism automatically moves the targets toward inoperative position uponfailure of the control mechanism. The

outer gas deflecting surfaces 106 and 108 of the targets are shaped so that the stream of gases will force the targets toward the inoperative position of FIG. 5. Further, a target return biasing means is provided in the form of tension springs 148 and 150 which will continually bias the targets toward inoperative position. These springs are connected between the push rods 122 and 124 at either side of the nozzle, and to the transient rails 28 and 30. It will be notedthat the inner surface 152.cf the inner shell 56 ofthe control nozzle 52 is spherical in shape. This spherical surface will combine with the inner concave surfaces of the deflector members 106 and 108 of the ing reverse thrust.

100 and 102 for reinforcingthe reverse, thrust when the control nozzle 52 is at the extended position. The 'inner'gimbal ring 64 has an inwardly beveled forward 7 surface 154 to also aid in deflecting the gases forwardly.

,Surfaces 154 and l56are gas deflectors, set at approximately 30' to" the axis of the'nozzle. The flowof gases is laterally to each side of the nozzle, as indicatedby the arrows 158 160 in FIGURE 6. It will also be seen *in that figure thatthe triangular extensions 26 of the fuselage gas protecting tube prevent the rearwardly deflected gas from flowing downwardly or upwardly in a vertical direction to engage the aircraft or othermecha- 1 nism which may be employed to support the nozzle.

nozzle extension 52 from the support nonle 96 and pro- The thrust reversing target vide aspace therebetween. members and 102 then pivot laterally into the gas stream to deflect the flow laterally and cause an increas- The preferred configuration of the variable area control nozzle 52 is shown in FIGS. 9 and 10, with the nozzle being shown circular in theother drawings for simplicity 'of explanation. In other figures, with the exception of FIGURES 8 to 12, the ,vortex generators 170 are also omitted. .l i i Thenozzle openings of each of the inner shell 56 and the outer shell 58 are scalloped to form a scalloped edge. This provides axially extending recesses 162 with projections 164 therebctween in the inner shell 56. Corresponding recesses 166 are provided in the ,outer shell with projcctions168. As the outer shell is rotated with respect to the inner shell by action of theshell rotation cylinder 62 to extend the piston rod 64 of the cylinder, the projections 168 of the outer shell move progressively over the recesses 162 of the inner shell to gradually reduce the elfective cross-sectional area until a position of minimum area is reached, as illustrated in FIG. 10.

The variable area nozzle isv shown in its preferred form with six scallops, I have found that the effectiveness of six scallops obtains advantages in reducing effective noise energy. In the jet noise problem, it has been foun'd'that the predominant sound energy produced by a jet shifts to higher frequencies as the dimensions of the jet are reduced. A resulting increased effective noise reduction occurs because of a greater loss of high frequency sound energy in passing through the atmosphere. The highest noise levels from a jet engine are-mainly in the 300 to 600 cycle per second range. A nozzle configuration of. six scallops or corrugations is ,eflective in the cycle per second to 2,400 cycle per second range.

The nozzle design results in an effective nozzle area wherein a main jet is provided in addition to a plurality of smaller jets with the resultant reduced noise eiiects. Further, the scallops on the nozzle will encourage jet mixing more rapidly than a circular nozzle because'of a larger peripheral area. It has been found that a nonle shaped inlaccordance with the principles of my'invention relieves the screech conditions at choked nozzle setting. The nozzle has also been found to reduce the overall sound pressurelevel, without appreciable loss of thrust. To improve the sound attenuation effects, a vortex generator is provided.

The vortex generator is shown at 170 in FIGURES 11 and 12, and is secured at the tip 164 of the scallop on the inner shell 56. The generator consists of an inward radially extendingknife blade 172 with the leading edge 174 forming a concave arc. The trailing end 176 of the knife blade 172 carries a spherically-shaped ball 178. This combination erator separates the small jets created by the scallops from the large jet and a vortex generator is mounted on the inside of each of the scallops. As the gas stream flows rearwardly through the nozzle it first encounters the concave leading edge 174 of the radial knifeblade jl72, whichextends radially inwardly inside the scallops,

and radialpaths of separation are formed in the gas rate streams separated by radial paths of separation. It

is believed that this is the action of the vortex generator which has been 'found'to cause a separation of the main flow stream.- The vortex generators are shown in detail of elements which forms the vortex gen 7 in FIGURES 11 and 12 but are omitted from the rest of the drawings for more clearly describing the other features in connection with the other drawings.

In separating the small jets created by the scallops from the large jets, the total jet stream is divided into a plurality of smaller streams which effectively reduce the noise level.

The controls are shown in FIGS. 13 and 14 in a schematic form. It will be understood that each of the controls may comprise a pivotally movable lever which moves through the positions shown in the diagrams 13 and 14. The throttle control is shown in FIG. 13 at 192 and controls the output of the combustion chamber 20, FIGS. 1 and 6. As the control arm is moved in a clockwise direction from the off position, the discharge of thrust gases increases to the point indicated at Max. whereupon further movement of the throttle lever will move the engine into the afterburner range, as indicated by the symbol AIBJQ The nozzle control may be operated independently when the control is set in the extreme right position of FIG. 14, as indicated by the diagram 194, a separate control operates the position of the gimbal ring to control the position of the directional control nozzle unit 52. Moving the control arm from the forward position to the reverse position will move the arm into the nongimbal range. In this position the gimbal rings are locked so that the directional control nozzle is centered axially and no directional components of thrust are obtained. In this range, the reversing targets are brought into the gas stream to reduce the forward thrust and increase the reverse component of thrust. 7

At a location indicated on the diagram 194, a point of zero thrust is reached and the reversing targets are shown in this position in FIG. 8. The targets 100 and 102 are maintained in this position with the throttle control set at maximum during landing touchdown conditions during which full power is available with full thrust in a reverse or forward direction being substantially instantaneously available by merely changing the position of the control nozzle elements. For a full reverse thrust, the control 1 94 of FIG. 14 is moved to the reverse position and for a full forward thrust it is moved to the forward position.

Reviewing the operation of the variable control nozzle, the positional variance of the elements for obtaining horizontally varying lateral thrusts is illustrated in FIG. 2. The outer gimbal ring 74 is turned on its trunnions 82 and 34 by operation of the hydraulic control cylinder 86, which is mounted on the transient rail 28. For lateral directional thrust, the rails are drawn in their withdrawn position with the directional control nozzle 52 brought up tightly against the support nozzle 96.

The variance in position of the control nozzle 52 to obtain vertical components of thrust is shown in FIG. 3. For this purpose, the inner gimbal ring 64 is tilted on its trunnions 70 and 72 by operation of the hydraulic control cylinder 76. The support rails 28 and 30 remain in their withdrawn position with the control nozzle 52 continuing to be drawn against the support nozzle 96. It will be recognized that the control nozzle can assume an infinite number of radial positions for radial thrust in any direction. It will also be recognized that the control cylinders 86 and 76 are positioned safely out of the jet stream, and will be out of the jet stream when the unit is in reverse thrust position.

Variance of the nozzle size is obtained by rotating the outer shell 58, FIG. 10, with respect to the inner shell 56. This is obtained by operation of the hydraulic cylinder 62 which is mounted on the inner gimbal ring 64. As the outer shell is rotated its scalloped edges cover the openings in the scalloped edge of the inner shell to reduce the effective nozzle size.

To adjust the nozzle to reverse thrust position, the transient rails 28 and 30 move the control nozzle 52 rearwardly a distance spaced from the support nozzle $6. The reversing targets and 102, as illustrated in FIG. 8, in their zero reverse thrust position are oariied rearwardly on the transient rails 28 and 30. As the target members 100 and 102 are pivoted inwardly toward the jet stream the component of reverse thrust increases until a zero thrust position is reached as shown in FIG. 8. Continued movement will reach a position of maximum reverse thrust, as shown in FIG. 6. The targets are so designed that the targets tend to move toward a position of zero reverse thrust to avoid accidental attainment of increased reverse thrust due to 'failure of the operating mechanism.

The control nozzle is operative to reduce the noise level in a still further Way by moving the reversing targets to a partial reverse position out of the gas stream with the nozzle actuated to its maximum area. In this position of the elements, the unit operates as a secondary air ejector. The air will cool the jet exhaust and decrease the sound power by a very significant amount which is valuable during taxi and engine check runs.

In the extended position of the control noule 52, the fuselage gas blocking tube 24 moves rearwardly. This prevents any of the prop'ellent gas from entering the fuselage and tail section of the plane, if used on a plane, and the tubes ties together the lower and upper transient rails 28 and 30 to help eliminate binding which would occur if two actuators were used for the rails. This also permits using a single actuator, although two are shown at 44 and 46.

When the control nozzle 52 is in the extended position and the reverse targets are used, the outer shell 58 is preferably rotated to a position of minimum nozzle area. Since both shells are spherical in shape, this provides the maximum spherical backing for the reverse thrust target members 100 and 102.

The directional control for operating the directional control nozzle 52 is preferably provided with a double actuator for moving the nozzle in each axis. This will assure a positive neutral position. The overall nozzle control, as shown in FIG. 15, in moving from the forward position to the reverse position, will move through the control areas as follows: forward thrust, non-directional control, ejector, zero thrust, directional control and reverse with directional control. The variable area nozzle may be automatically tied in the nozzle control and when the unit goes into reverse the variable area nozzle will close to increase the hemispherical area. I

Thus, it will be seen that I have provided an improved variable nozzle which meets the objectives and advantages hereinbefore set forth. The nozzle is capable of complete and effective control of the flow of jet thrust fluid, and may be controlled for rapid, effective and powerful control and accurate operation of the aircraft vehicle on which it is used.

It will be observed that the nozzle construction is comprised of elements which operate'interdependently, and which require a minimum number of elements, thus reducing the complexity of the control operational mechanism required. With the use of non-complicated eflicient complete control of the thrust, gases can be obtained for directional control thrust in an infinite number of lateral directions, as well as complete control of the thrust in a forward and reverse direction.

I The nozzle improves the sound attenuation and greatly reduces the noise level which is an important factor in aircraft use 7 I have, in the drawings and specification, presented a detailed disclosure of the preferred embodiments of my invention, and it is to be understood that I do not intend to limit the invention to the specific form disclosed, but intend to cover all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by my invention.

I claim as my invention: a

1. A jet propulsion nozzle for aircraft or the like comprising an exhaust duct with a gas discharge opening at the end for the expulsion of a propellant to obtain a forward propulsive thrust, a nozzle extension positioned at the opening of the duct and having a central gas discharge opening, said extension nozzle having a scallopshaped nozzle edge, an adjustment member rotatable relative to the nozzle extension and also provided with an opening with a scalloped edge whereby rotation of the adjustment member will decrease or increase the total effective nozzle'area, transient rails movable parallel to the flow of gas and supporting the nozzle extension whereby the extension may be moved axially outwardly away from the opening at the end of the exhaust duct, a gim- 'bal ring support for the nozzle extension for movement in a universal direction, operating members mounted on the transient rails for tilting the nozzle extension on its gimbal ring support to obtain lateral components of thrust for directional eflects, means mounted on the gimbal ring support for operating the nozzle adjustment memher, a pair of opposing target members pivotally mounted on the transient rails and movable between an ineffective position out of the gas flow stream and a position of reverse thrust in the gas flow stream, means for pivotally positioning the target members, means urging the target members to a position of decreased reverse thrust, means for axially moving the transient rails to adjustably position the thrust reversing targets and nozzle extension in an axial direction, a tubular shaped aircraft fuselage gas protecting tube surrounding the duct and connected to move with the transient rails whereby the protecting tube moves into place as the target members are moved into location beyond the end of the duct, and tr knife edge member with a ball at the end mounted at the end of the projections of the scalloped edges of the,

nozzleto separate the individual jet streams formed by the scallops.

2. A nozzle assembly for a jet propulsion engine comprising a nozzle member having a fluid conducting open- 10 at a location between the nozzle extension and extended nozzle, and control means operable to move the targets a to partial reverse position out'of the gas stream and to References Cited in the file of this patent UNITED STATES PATENTS 2,426,833 Lloyd Sept.2, 1947 2,472,839 Kramer June 14, 1949 2,481,059 Africano Sept. 6, 1949 2,486,019 Goddard Oct. 25, 1949 2,510,506 Lindhagen et a1. June 6, 1950 2,551,372 Haltenberger May 1, 1951 2,590,272 Robertson et a1 Mar.-25, 1952 2,612,747 I Skinner Oct. 7, 1952 2,620,622 Lundberg Dec. 9, 1952 2,648,192 Lee Aug. 11, 1953 2,650,752 Hoadley Sept. 1, 1953 2,696,079 Kappus Dec. 7, 1954 2,699,645 Oulianolf Jan. 18, 1955 2,735,264 Jewett Feb. 21, 1956 2,753,684 Greene July 10, 1956 2,780,059 Fiedler Feb. 5, 1957 r 2,841,954 Rainbow July 8, 1958 2,847,823 Brewer Aug. 19, 1958 2,849,861 Gardiner et al Sept. 2, 1958 2,857,119 Morgulofl Oct. 21, 1958 2,865,169 Hausmann Dec. 23, 1958 2,870,600 Brown Ian. 27, 1959' 2,886,946 Parker May 19, 1959 2,934,889 Poulos May 3, 1960 FOREIGN PATENTS 1,025,827 France Ian. 28, 1953- 1,092,654 France Nov. 10, 1954 1,134,418 France Dec. 3, 1956 (Corresponding British Patent 778,008, July 3, 1957) 1,150,555 France Aug. 12, 1957 1,150,556 France Aug. 12, 1957 103,325. Great Britain Jan. 19, 1917 739,500 Great Britain Nov. 2, 1955 740,385 Great Britain Nov. 9, 1955 OTHER REFERENCES Withington: Noise Control, Aviation Age, age 48- i 1 53, April, 1956. 

